We have 3 nurtures that have multiple emails with A/B testing. I need a report/dashboard that will show ALL email results (open rate, CTR, CTOR, etc.), including the A/B testing versions.
Is there anyway Marketo can do that? Is there an outside tool that might help with this?
Outside tool, yes. If the data was exported correctly into a BI tool you could model it how you want.
Within Marketo, unfortunately not. Within a given report, if an email has an A/B test on it with something like Subject Line, the only way to get at results for individual emails is to put a smart list filter over the top of the report with "Was Sent Email: (email name)" and a constraint of "Test Variant: A". You can't do this for multiple emails and have the report spit out the holistic results, unfortunately.
Instead, you could potentially split out each email A/B test into two individual emails, then use either a email send choice step or similar to do the random distribution. Then reporting on each email pair will give you the difference. Not sure if that's exactly the output you want though, and it's a workaround that might be a bit painful.
the best BI tool is the one the rest of your business is already using (i.e. leverage internal skills).